tonyf, it's very difficult to try to diagnose problems such as this, sight unseen. We have no idea what the potting mix is like, if your plant has been potted for a long time in the same soil, if it has been chronically over or under watered, over or under fertilized, and so forth. I will tell you that many (of not most) of the problems associated with container grown plants come from problems with the soil mix/root system/cultural problems.

If you can give us some history of the plant, and answer some of those questions I've mentioned, maybe we can help narrow the problem down.